MASTER-Kislovodsk: bright dwarf nova outburst
ATel #7972; O. Gress, V. Lipunov, E. Gorbovskoy (Lomonosov MSU), D. Buckley (SAAO), V. Kornilov, N. Tiurina, P. Balanutsa, I. Gorbunov, A. Kuznetsov, V. Vladimirov, D. Vlasenko, V. Chazov, E. Popova (M. V.Lomonosov Moscow State University, Sternberg Astronomical Institute), S. Potter, M. Kotze (South African Astronomical Observatory), N. M. Budnev, K. Ivanov (Applied Physics Institute, Irkutsk State University), A. Tlatov, D. Dormidontov, V. Senik (Kislovodsk Solar Station of the Pulkovo Observatory), V. Krushinski, I. Zalozhnykh (Ural Federal University), Yu. Sergienko, A. Gabovich, V. Yurkov (Blagoveschensk Educational State University)
on 31 Aug 2015; 14:12 UT
Credential Certification: Nataly Tyurina (firstname.lastname@example.org)
Subjects: Optical, Request for Observations, Cataclysmic Variable, Transient, Variables
MASTER OT J181523.78+692037.4 discovery - dwarf nova outburst, Ampl>6.3m, only Galex source
MASTER-Kislovodsk auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 18h 15m 23.78s +69d 20m 37.4s on 2015-08-28.76697 UT.
The OT unfiltered magnitude is 15.7m (limit 18.7m).
There 3 images with OT in MASTER-Kislovodsk database and there are 2 images with this OT in MASTER-Tunka on 2015-08-31.553UT with unfiltered m_OT=16.1. There is no minor planet at this place.
We have reference image without OT on 2015-06-11.925 UT with 19.3m unfiltered magnitude limit.
There is only GALEX source with only Ultraviolet NUV=22.815. So we can suggest the dwarf nova outburst with amplitude more then 6.3m.
Spectral observations are required.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/MASTEROTJ181523.78+692037.4.jpg
List of Optical Transients discovered by MASTER
MASTER Global Robotic Net